body {
    font-family: Arial, sans-serif;
    background-color: rgba(128, 0, 128, 0.5); /* 紫色半透明背景 */
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

form {
    background-color: rgba(255, 255, 255, 0.5); /* 白色半透明背景 */
    padding: 20px;
    border-radius: 5px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    width: 300px;
}

h2 {
    text-align: center;
    color: rgba(51, 51, 51); /* 深灰色半透明文本 */
}

.form-group {
    margin-bottom: 15px;
}

label {
    display: block;
    margin-bottom: 5px;
    color: rgba(102, 102, 102); /* 灰色半透明文本 */
}

input[type="text"],
input[type="password"] {
    width: 100%;
    padding: 10px;
    border: 1px solid rgba(221, 221, 221, 0.5); /* 浅灰色半透明边框 */
    border-radius: 5px;
    box-sizing: border-box;
}

input[type="submit"] {
    width: 100%;
    padding: 10px;
    background-color: rgba(128, 0, 128, 0.5); /* 蓝色半透明背景 */
    color: #fff;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

input[type="submit"]:hover {
     background-color: rgba(255, 192, 203, 0.90); /* 浅粉色半透明背景 */
    color: #000; 
}

a {
    text-align: center;
    display: block;
    margin-top: 15px;
    color: rgba(51, 51, 51,0.5); /* 蓝色半透明文本 */
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
    color:rgba(255, 255, 255, 0.90);
}

/* 针对小于600px宽的屏幕 */
@media (max-width: 600px) {
    form {
        width: 90%;
        padding: 15px;
    }

    label,
    input[type="text"],
    input[type="password"],
    input[type="submit"],
    a {
        font-size: 14px;
    }
}

/* 针对小于400px宽的屏幕 */
@media (max-width: 400px) {
    form {
        padding: 10px;
    }

    label,
    input[type="text"],
    input[type="password"],
    input[type="submit"],
    a {
        font-size: 12px;
    }
}